Participants received one of three messages that promised them pizza, comliments, or a cash bonus if they assembled a certain amount of computer chips that day; there was also a group that received no message which served as the control.

The first day, pizza was the top motivator, increasing productivity by 6.7 percent over the control group; compliment was close behind at 6.6 percent, while the cash bonus (approximately USD30) trailed considerably behind at 4.9 percent. It only got more interesting as the experiment continued; those who were promised a cash bonus performed 13.2 percent worse than those in the control group on the second day.

Overall, compliments turned out to be the best motivator, though Ariely believes that pizza would have won out had he had it his way—deliver the pizza at home to any winning employee. "This way… we not only would give them a gift, but we would also make them heroes in the eyes of their families," he wrote in the book.

Of course, fair pay and a living wage is absolutely essential, but pizza is the tool you need to finally rule the world.